Thanks for all the responses so far.
Had a chance to go back to that dealer, asked to see that back again, here is a shot made with my camera phone, pretended I had an incoming call!
Crappy pix, I know, I know, but I don't own a digital camera, never will, and it would arouse suspicion on the part of that dealer if I took a picture of the back! This is to show that as odd as it sounds about this black plastic key, this one does exist!
Also, lacking a "invisible scale",using my own judgement it appeared as heavy as my older A24 back, so maybe it wasn't an all plastic back. Sure as hell looked that way.
So again thanks to all, but again if anyone has one like this, please post, let me know!
Thanks in advance
I had bought two, some years back, made (or at least named) by Hartblei. Even they had the metal and chromed release and also has the built-in slide holder a few years before it showed up on the real Hassy stuff. Wouldn't work with my ELM I had at the time - only the 500 CM. The little pin in the EL wouldn't stick out far enough to disengage the back's lock (as it's supposed to do upon firing).
Other than that, good backs.
"Beer is proof that God wants us to be happy."
A black key like that is not odd. I keep telling you!
Standard issue for some time now. Even on chrome trim magazines.
And as far as i know, it's not plastic.
Boy do I feel a little stupid... But I figured it out!